Vibrating Wire: another measurement principle for remote monitoring
At Crodeon, our goal is to make any sensor compatible with Reporter. Therefore, our goal is to develop sensor adapters for all the major measurement principles to allow our datalogger to read as many different sensors as possible. We're thrilled to announce that, thanks to our new adapter, vibrating wire sensors are now compatible with Reporter, making it your new favourite vibrating wire data logger.
What is ‘vibrating wire’?
A vibrating wire is a high-precision measurement principle used in geotechnical and structural sensors. As the name suggests, these sensors contain a small-diameter tensioned steel wire.
How it works
This wire acts much like a guitar string. When an external force (such as strain or pressure) is applied to the sensor, the wire stretches or relaxes. This change in tension directly alters the wire's resonant frequency: the tighter the wire, the higher the pitch (frequency) it produces when vibrated.
Instead of a physical guitar pick, the sensor uses an electromagnetic coil to "pluck" the wire.
- Excitation: A pulse of current through the coil makes the wire vibrate.
- Detection: As the wire vibrates back and forth, it cuts through the magnetic field, inducing an electrical signal in the coil.
- Calculation: This frequency is measured by a datalogger or digital readout, which then uses a mathematical formula to convert that frequency into a precise unit of force, pressure, or displacement.
What are vibrating wire sensors used for?
While these sensors are excellent for measuring pulling forces (tension), they are also adapted to measure water pressure, load, and temperature. Their primary advantage is that the signal is transmitted as a frequency rather than a voltage. This makes the data immune to electrical interference and allows for accurate readings even over several kilometres of cabling! This makes the vibrating wire sensor measuring principle the number one choice in sectors like geotechnics and structural engineering.
Where are vibrating wire sensors used?
This type of sensor is most frequently used in geotechnics and structural engineering. This means that the sensors are embedded within the ground and rock formations, or within structures. They can measure subterranean water level, or the forces within (underground) structures like tunnels, mines, foundations and more.
Vibrating wire sensors come with some interesting advantages, especially considering they're often embedded deep within structures in faraway, hard-to-reach places or structures with a long lifespan.
- No drift: these electro-mechanical sensors don't contain electronics that need to be recalibrated
- Low power: these types of sensors are low in power consumption, making them perfect for remote monitoring in locations that do not have access to the power grid. You can connect them to a solar panel or the battery bank.
What sensors use vibrating wire?
Many different kinds of sensors use the vibrating wire measuring principle. Note that some of these sensors also exist using other types of measuring methods.
- Temperature sensors
- Joint meters, deformometers, displacement sensors
- Pressure sensors, pressure cells
- Extensometers
- Tiltmeters
- Stress cells
- Piezometers
- Strain gauges
- Load cells
Are you looking to connect one of these sensors to Reporter, your new favourite vibrating wire data logger? The vibrating wire adapter is here to help!
